Infectivity of Hemophilus pertussis for the Chick Embryo

Abstract

H. pertussis was found to be highly infectious for the developing chick embryo when introduced via the yolk sac. As few as 5 organisms derived from Phase I cultures grown on Bordet-Gengou medium sufficed to initiate fatal infection. Organisms propagated in the yolk sac were of similar high virulence when tested by this route. Deaths occurred only irregularly following introduction of the organisms via the allantoic cavity, even though a considerably greater dosage was employed.